Demands for miniaturization of, for example, semiconductor devices and micro-electro-mechanical-systems (MEMSs) have been increasing. Recently, in addition to photolithography techniques, a microfabrication technique, which forms a pattern on a resist (photocurable composition) arranged on a substrate, such as a wafer, with a mold and forms a cured resist pattern on the substrate by light irradiation, has been getting much attention. The technique is called a photo-imprint technique and also is called a photo-nanoimprint technique because this technique can form nanometer scale fine structures on substrates. In photo-imprint, first, a resist is applied to a pattern-forming region on a substrate. Subsequently, the resist is brought into contact with a mold having a relief pattern on the surface. The resist is cured by irradiation with light, and the mold is then removed from the cured product. As a result, a photocured product having a relief pattern is formed on the substrate.
PTL 1 discloses an imprint method in which resist droplets are discretely arranged on a substrate by an ink jet system. In this method, the resist spreads by abutting contact with a mold and infiltrates into the gaps between the substrate and the mold or into the recesses of the mold. Thus, the gaps and the recesses are filled with the resist. However, the gas among the droplets that have spread may remain as bubbles. The resist curing with bubbles remaining therein has a problem of producing a photocured product having an unintended shape.
PTL 2 discloses a use of a condensable gas that condenses by a capillary pressure generated by infiltration of a resist into the gaps between a substrate and a mold or the recesses on the mold. The condensable gas introduced between the mold and the substrate reduces its volume by condensation after the supply of the resist and accelerates the disappearance of the remaining bubbles. The condensable gas mentioned in PTL 2 is trichlorofluoromethane (CFCl3).
NPL 1 describes an improvement in filling ability by using 1,1,1,3,3-pentafluoropropane (CHF2CH2CF3) as a condensable gas.